package emailsender

import (
	"net/mail"
	"regexp"
	"strings"
	"time"

	"qoobing.com/gomod/email"
	"qoobing.com/gomod/email/smtp"
	"qoobing.com/gomod/log"
)

// ///////////////////////////////////////
// 发送器接口
// ///////////////////////////////////////
type Sender interface {
	Send(to string, name, body string) error
	SenderType() string
	SenderSupportAddressType() string
}

type Config struct {
	Id        string   `toml:"id"`        //id
	Type      string   `toml:"type"`      //必选，发送器类型
	Smtp      string   `toml:"smtp" `     //必选，SMTP服务器地址（含端口）
	From      string   `toml:"from"`      //必选，发件人
	DryRun    bool     `toml:"dryrun"`    //可选，只执行发送流程，但不真实发送
	SmtpUser  string   `toml:"smtpuser"`  //可选，SMTP授权人地址，默认时从from中取
	SmtpPass  string   `toml:"smtppass"`  //可选，SMTP授权人密码，默认时从from中取
	SmtpProxy string   `toml:"smtpproxy"` //可选，SMTP代理地址，默认时为空
	WhiteList []string `toml:"whitelist"` //可选，发送白名单，默认为空
	BlackList []string `toml:"blacklist"` //可选，发送黑名单，默认为空
}

func (cfg Config) GetId() string {
	return cfg.Id
}

func (cfg Config) NewSender() (Sender, error) {
	return New(cfg), nil
}

type EmailPlainAuthSender struct {
	cfg  Config
	send func(to string, name, body string) error
}

func New(cfg Config) *EmailPlainAuthSender {
	var (
		arrFrom  = strings.Split(cfg.From, "/")
		fromName = arrFrom[0]
		fromAddr = arrFrom[1]
		fromPass = arrFrom[2]
		arrSmtp  = strings.Split(cfg.Smtp, ":")
		smtpAddr = arrSmtp[0]
		smtpPort = arrSmtp[1]
		smtpUser = cfg.SmtpUser
		smtpPass = cfg.SmtpPass
	)
	if smtpUser == "" {
		smtpUser = fromAddr
	}
	if smtpPass == "" {
		smtpPass = fromPass
	}

	type emailItem struct {
		to   string
		name string
		body string
	}

	var whiteListRegs = []*regexp.Regexp{}
	for _, r := range cfg.WhiteList {
		whiteListRegs = append(whiteListRegs, regexp.MustCompile(r))
	}
	var blackListRegs = []*regexp.Regexp{}
	for _, r := range cfg.BlackList {
		blackListRegs = append(blackListRegs, regexp.MustCompile(r))
	}
	var addressInWhiteList = func(address string) bool {
		for _, reg := range blackListRegs {
			if reg.Match([]byte(address)) {
				return false
			}
		}
		if len(whiteListRegs) == 0 {
			return true
		}
		for _, reg := range whiteListRegs {
			if reg.Match([]byte(address)) {
				return true
			}
		}
		return false
	}

	var emailQueue = make(chan emailItem, 1024)
	var emailSendFunc = func(to string, name, body string) (err error) {
		eml := emailItem{to, name, body}
		emailQueue <- eml
		return nil
	}
	var emailSendFuncInner = func() {
		defer func() {
			if re := recover(); re != nil {
				log.Errorf("email inner sender exit with recover: %v", re)
			}
		}()
		for {
			eml, ok := <-emailQueue
			if !ok {
				log.Infof("emailQueue closed")
				return
			}
			log.Infof("start send email to [%s]", eml.to)
			if !addressInWhiteList(eml.to) {
				// white-blck-list
				log.Infof("send email to [%s] ignored for not in white list.", eml.to)
				continue
			} else if cfg.DryRun {
				// dryrun mode
				log.Infof("end send email to [%s]: ignored for dryrun mode.", eml.to)
				continue
			}
			// compose the message
			m := email.NewHTMLMessage(eml.name, eml.body)
			m.To = []string{eml.to}
			m.From = mail.Address{Name: fromName, Address: fromAddr}
			// send it to smtp server
			auth := smtp.PlainAuth("", smtpUser, smtpPass, smtpAddr)
			addr := smtpAddr + ":" + smtpPort
			if cfg.SmtpProxy != "" {
				addr += "|" + cfg.SmtpProxy
			}
			if err := email.Send(addr, auth, m); err != nil {
				log.Errorf("failed send email to [%s]", err.Error())
				log.Infof("to[%v],from[%s]", m.To, m.From)
				log.Infof("smtpUser[%s],smtpPass[%s],smtpAddr[%s:%s],smtpProxy[%s]",
					smtpUser, secLogPass(smtpPass), smtpAddr, smtpPort, secLogProxy(cfg.SmtpProxy))
				continue
			}
			log.Infof("success send email to [%s]", eml.to)
		}
	}
	go func() {
		for {
			emailSendFuncInner()
			log.Infof("email inner sender exit abnormal, restart it 5s later...")
			time.Sleep(5 * time.Second)
		}
	}()
	var sender = &EmailPlainAuthSender{
		cfg:  cfg,
		send: emailSendFunc,
	}
	return sender
}

func (sender *EmailPlainAuthSender) Send(to string, name, body string) error {
	return sender.send(to, name, body)
}

func (sender *EmailPlainAuthSender) SenderType() string {
	return "EMAIL" // SENDER_TYPE_EMAIL
}

func (sender *EmailPlainAuthSender) SenderSupportAddressType() string {
	return "EMAIL_ADDRESS" // SENDER_SUPPORT_ADDRESS_TYPE_EMAIL_ADDRESS
}

func secLogPass(password string) string {
	n := len(password)
	if n < 3 {
		return "*****"
	} else if n < 8 {
		return "***" + password[n-2:]
	}
	return "" + password[:1] + "**" + password[n-2:]
}

func secLogProxy(proxy string) string {
	if strings.HasPrefix(proxy, "socks5://") && strings.Contains(proxy, "@") {
		arr := strings.Split(proxy, "@")
		if len(arr) == 2 {
			return arr[1]
		}
	}
	return proxy
}